update dtjava.js to offer to install cobundle

Starting 2.2 we need to differentiate what we should offer to install if installation is needed depending on application requirements.

If app insists on JRE 6 and it is windows platform we should offer to install standalone JavaFX.
It is cobundle instead.

We should also change logic to validate whether requirements are met as whether we have FX or not depends on what version of JRE we will be using ...